Hydraulic press



June 25, 1940. R. w. DINZL HYDRAULIC PRESS Filed April 4, 193a 3 Sheets Sheet 1 3 if; INVENTOR B. W D INZL.

Jame 25, w. w. 0mm

EYDRAULIC PRESS 1mm April 4. 1958 3 Sheets-Sheet 2 INVENTOR B. W DINZL AT ORNEY Patented June 25, 1940 r RAULIC PRESS Richard W. Dinzl, Westfield, N. L, assignor, by mesne assignments, to The Baldwin Locomotive Works, a corporation oi Pennsylvania Application April 4, 1938, Serial No. 199,962 r 8 Claims.

This invention relates generally to hydraulic presses, particularly of the type employing multiple slides each operated by a plurality of rams and cylinders.

Hydraulic presses of the foregoing type are used especially for stamping or forming large sheet'metal products, such as automobile bodies, thereby involving die and blank holding slides of large dimensions. Such large size slides are operated by a plurality of rams and cylinders located usually at two or more points offset from the vertical center line of the press. The rams v are ordinarily subjected to substantially the same fluid pressure and hence if one portion of the slide should offer greater resistance to movement than another portion, the slide will tilt out of parallelism with the base. This causes the dies to be improperly matched resulting in an inferior orv defective stamping. The possibility of tilting is, of course, further aggravated by the large size of the slides and the enormous operating forces employed.

Many attempts have been made to provide mechanical and hydraulic arrangements for coordimating the operation of the plurality of rams but without success on account of either the complications and the cost incident thereto or the uncertainties of positive operation. In other attempts, presses have been built which are partly hydraulic and partly mechanical, such as hydraulically operated toggle presses. The toggle mechanism is a characteristic operating mechanism of mechanical presses and provides a positive means for preventing tilting of the slide.

:7 However, this is complicated and expensive, and in addition has many disadvantages incident to mechanical type presses and also does not allow certain extremely desirable characteristics of a hydraulic press to be fully obtained. Further attempts to overcome tilting in a full hydraulic 40' press have consisted in making the usual guides and guideways at the edges of the slides of great length and surface area but this involves considerable expense and a very undesirable increase in height of the press as well as causing the guide- 45 ways to be subjected to possible scoring in resisting the tilting action of the large dimension slides. It'will be understood; that if any tilting occurs, it not only throws the slide out of parallelism but in doing so it tends to force the press 50 frame or guideways apart by a powerful twisting action of the slide and additionally creates excessive localized pressure on the guideways. This subjects the guideways to excessive wear and subjects the press frame to unnecessary forces.

It is an object of my invention to provide an (Cl. ins-t5) improved combination in'a full hydraulic press so as to obtain all of the advantages of both hydraulic and mechanical presses without incurring the disadvantages of either thereby allowing a large slide to be efiectively operated by 5 a multiplicity of rams. In accomplishing this and other objects, I have provided an improved two directional equalizing arrangement specifically applied to the inner slide of a multiple slide press so as to effectively avoid tilting and I have 10 arranged the operating rams and equalizing mechanism in a simple, compact and economical manner while at the same time maintaining maximum rigidity of the press structure with minimum length and'area of the guideways. As a re- 15 sult, full hydraulic presses have been built embodying all the desirable characteristics of both hydraulic and mechanical presses without incurring the disadvantages of either.

A still further object is to provide improved 2o bearing blocks between the slides and their guideways so as to insure maximum smoothness and ease of operation with minimum maintenance cost of the guide structure. Another object is to provide improved means for providing various 25 degrees of blank holding pressure by the outer slide at various points around its perimeter thereby to allow certain portions of the sheet metal blank to slip more readily than other portions during a drawing operation. A further .object is to provide in a compact space an improved combination between a single integral bottom slide and a base so as to maintain a high degree of rigidity of the base and slide together with a simple and positive means for uniformly operating the slide.

Other objects and advantages will be more apparent to those skilled in the art from the following description of the accompanying drawings in which:

Fig. 1 is a vertical longitudinal section taken substantially on the ofiset line i--|l of the plan view shown in Fig. 3;

Fig. 2 is a vertical transverse section taken on the line 2--2 of Figs. 1 and 3;

Fig. 3 is a plan view of Fig. 1;

Fig. 4 is a horizontal section taken substantially on the line 4-t of Fig. 1;

Fig. 5 is'an enlarged vertical section through the improved guide block taken substantially on the line 5-5 of Fig. 4;

.Fig. 6 is a vertical longitudinal section through the base and lower slide;

Fig. 7 is a diagrammatic plan view of the base.

In the particular embodiment of the invention such as is disclosed herein merely for the purpose of illustrating one specific form among possible others that the invention might. take in practice, I have shown a multiple slide hydraulic press comprising generally side columns I and I Z mounted upon a suitable base 3 and supporting a cross member 4 at their upper ends. As is customary in large presses, the cross member, base and side columns are held together by large tension rods and nuts 5 located at each of the four corners of the press structure as shown in Figs. 3 and 4. An outer slide 6 is vertically guided on tapered guideways l which as shown in Fig. 4 are formed on L-shaped, members 8 supported against machined surfaces on the inner sides of columns i and 2 while bolts 9 are secured to the columns for adjusting the tapered guideways inwardly and outwardly. To accommodate an inner slide 'ii within the outer slide,

thelatter is provided with vertical guiding sur-.

faces i arranged diagonally across each of the four inner corners of the outer slide. The inner slide is disposed within the hollow interior I! of the outer slide and is provided at each corner with improved swivel bearing blocks generally indicated at i3. Each block, as shown in Fig. 5, comprises a wedge-shaped wear strip I?) supported upon an inclined surface of a backing member it. A bolt It moves the wear strip axially to effect lateral adjustment thereof. The backing member is provided with an arcuate boss i6, preferably semi-spherical, bearing against a machined surface I? formed at the inner end of a rectangular recess it. The opposed side walls of this recess laterally support the wear strip i3 and backing member i6 while a lower shoulder is formed integrally with the inner slide and an upper keeper bar 20 bolted thereto retain the backing member I l in vertical position and permits sufficient movement of the swivel bearing blocks to insure at all times uniform bearing contact with the guide surfaces iii.

The inner slide is normally held in its upper position by pullback cylinders 22 and pistons 23, these pullback cylinders being two in number and located at diagonal points with respect to the center of the machine as shown in the plan view of Fig. 3. The pistons 23 are secured in any usual manner to the inner slide by nuts at, Fig. l. The cylinders 22 extend through the cross member 8 preferably by being inserted therein from the under side thereof and are held thereto by bolted flanges 28. Main operating cylinders 2i also extend through the cross member d from the under side thereof and are held thereto by bolted flanges 28 similar to the pullback cylinders. Main operating rams 29 are connected the inner slide preferably through an interposed connection 30 which has a semi-spherical seat 3! to which the ram is held by a center bolt 32, The main cylinders 21 are preferably, two in number and as shown in the plan view of Fig. 3 are located at diagonal points with respect to the center of the machine and also in transverse alignment with the pullback cylinders 22.

The pullback cylinders 22 are adapted not only to raise the inner slide but also to raise the outer slide through bosses 33 projecting outwardly from the inner slide so as to be overlapped by bosses 34 projecting inwardly from the outer slide. A spring cushion mechanism generally indicated at 35 is preferably supported by bosses 34 to provide a yielding contact for bosses 33. Each end of the slides is preferably provided with live of the foregoing cushioning devices. The outer slide is normally employed as a blank holding slideand the blank holding pressure is produced by cylinders 31 and rams 38 preferably four in number located at each of the four corners of the outer slide as shown in the plan view of Fig. 3. The cylinders 31, like the pullback and main operating cylinders, are disposed within the cross member I by extending upwardly therethrough from the under side thereof and secured in position by bolted flanges 39. r

The foregoing arrangement of rams and cyl- -inders with respect to cross member 4 provides a very compact and rugged arrangement with minimum vertical. dimension of the press and without placing any limitations on the operating characteristics, effectiveness or flexibility of operation of the press. To maintain these desirable characteristics and at the same time insure mini a very substantial tongue 48 formed rigidly with inner slide ii. This tongue could be formed integrally with the inner slide but is preferably formed as a separate element rigidly connected to the slide by being tightly fitted in stepped annular surfaces M and 62 formed in a tapered opening 63 which is located along the central vertical axis of the slide and press. The tongue has. a large diameter lower portion thereby insuring maximum rigidity between the slide and tongue whfle the upper portion thereof has a long tapered upper portion M. The upper free end-thereof has a crosshead 85 pivotally connected thereto as at to. The tongue is of maximum length consistent with maintaining the overall height of the press at a minimum. The crosshead is vertically guided in a crosshead guide generally'indicated at 47 formed as part of the upper cross frame mem- I her 6. For instance, the cross member 6 has a central vertical opening surrounded by upwardly and downwardly extended flanges t8 and 69 within which opposed wearing blocksdd and Bi are secured in any suitable manner. These wear.- ing blocks have preferably V-shaped guide surfaces 52 and Eiicomplementary tn the guide surfaces on crosshead 5b.

a The foregoing relation of the slide, tongue and frame cross member 4 is such that any unequal loadingof the inner slide will cause the latter to swing laterally about the crosshead pin 68. Due to the extended distance of this pin from the slide and the fact that this relation is maintained throughout full vertical movement of the inner slide, it is seen that any unequal forces will merely cause the inner slide to bear laterally and uniformly against the entire guide surfaces of the slides with no twisting or distorting action of the slide and hence the slide will be maintained inparallelism with the base of the press. Hence this arrangement insures maximum accurate nesting of the complementary dies particularly in presses of large size and power. The location of the flanged structure 48 and I! not only permits reinforcement of the cross frame member l with mininriim amount of material but also permits the space, that would be ordinarily con-' sumed solely by the cross member, tobe eflec-' tively utilized in the above described functional relation to the inner slide. The operation of 68 and 69 members it.

til

' its stop and prevent by a cross bar 65.

outer slide through the slide guideways therefor.

It is sometimes desirable to have one portion of a blank held with a less force than other portions thereof thereby to permit the blank to slip slightly from beneath the blank holding slide during a drawing operation. In hydraulic presses, difliculty has heretofore been experienced in obtaining this desirable characteristic in a simple and efiective manner in view of hydraulic pressure acting equally on the blank holding rams 38.

.In my improved arrangement I have provided a very simple structure comprising preferably a four point pressure control of the outer slide by means of screws 55 adjustably threaded in nuts 56 which'are bolted as at 51 to the sides of outer slide 6. Nuts 58 lock the screws in whatever vertical position they may be adjusted. Adjustment is obtained by applying a suitable wrench to openings in enlarged heads 59 of the screws. These screws and nuts are four in number located substantially at the corner of the outer slide. If the screws are all adjusted so. as to never contact suitable stops 60 formed on columns l and 2, Figs. 1 and 2, then the slide will uniformly hold the blank under the pressure in the blank holding cylinders. However, toallow slippage of only one portion of the blank, the screw adjacent said portion is adjusted downwardly so as to engage the innerslide from moving down on to that portion of the blank with the full force that is portions of the slide. of the screws can be similarly adjusted.

To provide uniform and stable operation of a lower slide of large dimensions while at the same time providinga base of. great rigidity without an excessive amount of material, I form the slide of substantially U-shaped formation comprising two tables 63 and M connected at their bottom Cushion cylinders 66 engage the side portions of the slide, while an operating ram El is connected to the cross portion 65. The press base comprises two box-like end members connected as shown in Fig. 7 by side Extending transversely between and connecting the side members it is a cross bar ll arranged to be receivable within a vertical recess l2 formed between the ,two side portions 63 and 64 of the U-shaped slide. Also the lower edge surface "#3 of the member N forms an upward limit stop engageable with the cross portion 85 of the slide while each corner between cross bar 65 and side portions Mend M has vertical guideways l5 and it for slidably supporting the slide. This provides an extremely compact and stable arrangement having maximum rigidity at minimum cost together with allowing uniform and simultaneous operation and movement of the multiple tables tit and 64 when operated by ram li'l; This improved result is accomplished without sacrificing any rigidity or stability even though the parts are not excessively heavy which is a factor of great importance in large presses.

From all of the foregoing disclosures it is seen that I have disclosed principles and details of construction whereby hydraulic presses of extraordinary size and capacity may be built so' as to obtain all of the advantages of a full hydraulic press without incurring any disadvantages that have. heretofore been inherent in such presses, especially of the multiple cylinder and ram type. My improved press insures maximum uniform movement and maintenance of parallelism of a slide regardless of varying degrees of resistance at various points thereof. My improved lower exerted by the remaining If desired, more than one slide and. base construction is adapted to be made of minimum weight and strength and my improved guide blocks insure maximum wear and minimum cost of maintenance of the guideways notwithstanding that a press of this type is subjected to enormous loads and forces and is in constant use as a vital part of the production line when used in a mass production industry. A suitable pump supplies operating fluid to the cylinders under any desired or usual control system.

It will of course be understood that various changes in details of construction and arrangement of parts may be made by those skilled in the art without departing from the spirit of the invention as set forth in the appended claims. I claim:

1. Ahydraulic press comprising, in combination, a frame having side columns and an upper.

cross member connecting the same, a slide disposed between and laterally resisted by oppositely acting vertical guiding surfaces formed on said side columns, a plurality of hydraulic rams and cylinders respectively connected to said slide and to said cross member and constituting the sole power mechanism for effecting the working stroke of said slide, said slide and its connections with the rams constituting the only mechanical means purpose of supplementing the lateralresistance of said other guidingsurfaces, a tongue rigidly secured to said slide in eccentric relation to the axes of said rams and having "an upwardly projecting free end slidably supported by said crosshead guide, said tongue and crosshead guide being so constructed that they are operative in cooperation with said guiding surfaces on the side columns to resist with substantially equal efiectiveness in any lateral direction the whole of an eccentric load occurring anywhere on the slide and that upon occurrence of such eccentric forces the tongue and crosshead are subjected solely to lateral resisting forces, thereby to effect substantially identical movement of the rams and to prevent tilting of the slide regardless of any simultaneous difference in magnitude of the operating or work resisting forces acting simulit taneously on the ram and slide.

2. The combination set forth in claim .1 further characterized in that said crosshead guide extends vertically through said cross member substantially at the vertical center line of the press, and said hydraulic cylinders are supported .by and extend through said cross member at points diagonally. offset from said vertical center line. 1

3. A hydraulic press comprising, in combination, a frame having side columns and an upper cross member connecting the same, a slide disposed between said irame sides, a plurality of hydraulic rams and cylinders respectively connected to said slide and cross member, a crosshead guide supported by. said cross member, a tongue rigidly secured to. said slide and having an upwardly projecting free end terminating adjacent said crosshead guide, and means for slidably supporting said free end by said crosshead guide, said means for slidably supporting the free end of said tongue in said crosshead guide including a crosshead vertically slidably guided by said crosshead guide and pivotally connected to the 4. A hydraulic press comprising, in combination, a frame having side columns and an upper cross member connecting the same, a slide-disouter slide and side columns, an inner slide, oppositely acting guideways between said inner and outer slides, hydraulic cylinders and rams respecposed between and laterally resisted by said frame tively connected to said cross member and to sides, a plurality of hydraulic rams and cylinders respectively connected to said slide and cross member, a crosshead guide having a vertical opening extending entirely through said cross member from which flanges project both upwardly and downwardly to form a continuation of the crosshead guide opening and to reinforce the central portion of the cross member,

, wearing blocks disposed within said flanged opening, a tongue rigidly secured to said slide and having an upwardly projecting free end provided with a crosshead slidably guided by said wearing blocks, the connection of said rams and tongue to said slides and the lateral resistance by said frame sides comprising the principal mechanical means for effecting substantially identical movement of said rams regardless of variable operable forces applied thereto.

5. A hydraulic press comprising, in combination, a frame having side columns and an upper cross member connecting the same, a slide disposed between and laterally resisted by said frame sides, a plurality of hydraulic rams and cylinders respectively connected to said slide and cross member, a crosshead. guide supported by said cross member and having opposed guideway surfaces of -shape formation in plan view, a tongue rigidly'secured to said slide and having an upwardly projecting free end, and a crosshead connected to said free 'end and having complen'ientary surfaces slidably guided by said V-shape surfaces, the, connection of said r ms and tongue to said slides and the lateral re atance by said frame sides comprising the princip l mechanical means for effecting substantially identical move-' ment of said rams regardless of variable operatin combine said slides, said rams and cylinders constituting the sole power mechanism for effecting the working stroke of said slide, a tongue rigidly secured to said inner slide and extending upwardly .tosaid cross member, a crosshead guide supported by said cross member and having oppositely acting guiding surfaces which are arranged sol for the purpose of supplementing the lateral resistance of said other guiding surfaces, means for slidably supporting said tongue by said crosshead guide, the connection of said rams and tongue to said slide together with both of said guideways comprising the principal mechanical means foreifecting substantially identical movement of said rams regardless of variable operating forces applied thereto, and mechanical abutting means adjustably interposed between portions of said frame and said outer side for positively mechanically limiting movement of various portions of said outer slide regardless of the hydraulic pressure applied to the operating rams therefor thereby toestablish different simultaneously operative blank holding forces.

' '1. A hydraulic press comprising, incombin'ation, a frame having a base, side columns and a cross member connecting the same, an inner die slide, an outer blank holding slide, hydraulicrams and cylinders for operating said slides, and adjustable mechanical means interposed between said outer slide and base and being operative to, positively mechanically limit movement of said slide at various portions thereof thereby to establish diflferent simultaneously operative blank holding forces. v

8. The combination set forth in claim 7 further characterized in that said adjustable mechanical means includes a plurality of nuts carried by said outer slide and screws adjustably supported by said nuts for engagement with said 

